1. Field of the Invention
The present invention relates to a bone plate system and apparatus for bending bone plates; and more particularly, to a system that comprises readily formable bone plates and a bending and configuring tower designed to create a bone plate shape that matches a template.
2. Description of the Prior Art
Many patents address issues related to bone plates and apparatus for bending bone plates. Some of the patents relate to bone plates for human use while others relate to bone plates for canine use.
U.S. Pat. No. 2,737,835 to Herz discloses tools for bonding plates in bone surgery. A flat plate is bent at a suitable location using a bending tool. As shown above in FIG. 4, three Smith-Petersen nails are inserted in one of the broken femur bones and a fourth nail is inserted into the femoral shaft to rigidly hold the broken bones in place without movement, to promote bone healing. The plate used is a two-dimensional object. It does not completely support the three dimensional bone segments that have fractured; but relies on the nails to prevent movement of the bone plate.
U.S. Pat. No. 3,866,458 to Wagner discloses a bender for contouring surgical implants. The bender has a pair of bending tools, one of which is specifically adapted for use in bending a particular hip fixation plate and the other of which is adaptable for use on bending a wide variety of metallic surgical implants including a hip fixation plate. The first of the benders has an elongated handle portion conforming to the femur shaft and a flat bowl-shaped head portion conforming to the lower portion of the greater trochanter of a femur. The head portion has at least one transversing bore for receiving a hip screw. The first bender is designed to grip the head portion of the plate. It has an upper jaw and a lower jaw pivotally interconnected at one end. A swing bolt and wing nut are disposed on the other end. The inner surface of one of the jaws has one or more nipples for registering with transverse bores of the head portion. The inner surface of the other jaw is adapted to close against the side of the head portion facing it. An elongated handle is rigidly attached to the bottom of the lower jaw for gripping purposes. The second bender may be used to grip any generally flat implant having opposed sides. It has a housing with a channel extending longitudinally through it. One side of the channel is contoured to conform to the contour of one of the opposed sides of the implant. A jaw member is disposed within the channel. The jaw member is adapted for vertical movement, which raises and lowers the jaw member within the channel. An elongated handle extends from the housing for gripping purposes. The second bender is used by sliding the implant into the channel in the space between its one side and the jaw member. The jaw member is raised until the implant is clamped between it and one side of the channel. The bone plate disclosed by the '458 patent is clearly not suitable for multiple purposes.
U.S. Pat. No. 3,965,720 to Goodwm et al. discloses a hinge adjustment tool. This hinge adjustment tool is designed for use on self-closing hinges for kitchen cabinets. The hinge has the form of a bar of hot rolled steel. End portions of the bar are displaced out of the plane of the bar's intermediate portion. Such displacement is produced in opposite directions at an angle of about 45° by a cold bending operation. The end portions are provided with a slot opening facing in opposite directions, and with the end portions of the hinge tool hardened by heat treatment. This hinge is designed for self-closing kitchen cabinets. The ends of the hinge bar are bent in opposite directions, and are provided with slots facing the opposite direction. This hinge adjustment tool has a structure and function distinctly different from a multi-purpose bone plate for orthopedic applications.
U.S. Pat. No. 5,113,685 to Asher et al. discloses an apparatus for contouring spine plates and/or rods. A plurality of instruments or members plastically deform spine plates or rods to a configuration, which corresponds to a desired configuration for connection to a spinal column. A pair of flat benders having slots are engageable with a spine plate to bend and/or twist the spine plate. A pair of tube benders is engageable with a rod to bend the rod. One of the flat benders may be used with one of the tube benders to form a bend in the rod. In addition, the two flat benders may be used together to bend the rod. These instruments make possible two-dimensional bending of spine plates and three-dimensional bending of spine rods. The spinal plate disclosed by the '685 patent is not a bone plate. It is not used to fix broken bone; but rather keeps the spinal column in a desired position.
U.S. Pat. No. 5,564,302 to Watrous discloses orthopedic bone plate bending irons. The orthopedic bone plate bending irons comprise a simple machine that permits the application of a concentrated bending moment to a stiff metallic bone plate. The bends are accomplished along three orthogonal torsional axes, enabling a modest sized operator to bend the most stout bone plates. The bending moments are transmitted to the bone plates through the edges of curved apertures, so that the built in transverse curvature of the plate is not crushed with resulting weakening of the plate. Finally, the apertures are rotated and angled to provide comfortable hand clearance and to permit efficient application of muscle force by the operator. The bone plate is inserted into angled slots in a pair of irons and the distal end of the irons is moved to bend the bone plate. The bending action only bends the overall plate and portions of the plate cannot be contoured to fit a three-dimensional fractured bone. There is no template provided to adjust bending and twisting in accordance with surgical requirements.
U.S. Pat. No. 5,746,742 to Runciman et al. discloses a bone plate template. This bone plate template is composed of 1100-0 aluminum. It comprises reduced width connecting sections that have a width to thickness ratio of 1.6:1 to 1.4:1, so that these connecting sections may be manually bent or twisted without forming folds or kinks. The template disclosed by the '742 patent is not a template for a symmetrical bone plate; it cannot be used in both left handed and right-handed conditions. After the bone plate template is bent to desired shape, the actual bone plate must be bent by application of a large amount of force. This procedure causes the bone plate template with the desired shape to be bent out of shape during the bending operation of the actual bone plate. The template disclosed by the '742 patent is only a template; and provides no disclosure for bending a bone plate.
U.S. Pat. No. 5,904,684 to Rooks discloses a device and method for simultaneous bilateral pelvic osteotomies. This method and device facilitates the procedure of a transverse osteotomy of both ilium and a secondary osteotomy through the pelvic symphysis. A plate is utilized which has facility for attachment of eight screws into the, animal bone tissue to more securely hold the plate in place. The shape of the plate represents a significant advance and has important characteristics. Only one side of the plate has sharply angled surfaces to accommodate rotated pelvic bone portions, while the other side of the plate is smooth and facilitates a more stable direct insertion of the bone screws. In this configuration, the bores can closely match the shapes of the heads of the bone screws and provide less exposed material at the outside of the plate. The plate is adapted to be bent. More than ample material is provided to bend the plate along its axis to facilitate insertion of bone screws at right angles to the extent of the pelvic bone tissue. The bone plate has two wedge shaped elements, which are twisted and bent according to surgical requirements. It is not symmetrical, and cannot be interchangeably used for the left side and right side before bending. The bone plate is made of solid metal and cannot be easily bent into three-dimensional shapes.
U.S. Pat. No. 5,968,047 to Reed discloses a fixation device. A sterile bone fixation device in the form of a screw, pin or bone plate is made from sterile animal or human bone. Perforations are provided on the surface for improved bone bonding. The bone plate disclosed by the '047 patent is not bendable, and cannot be easily shaped to conform to the three dimensionality of a fractured bone.
U.S. Pat. No. 6,077,271 to Huebner et al. discloses a bone plate vise. The vise is provided as an aid in bending a bone plate. The vise includes an elongate handle and a first clamp mechanism. The clamp mechanism includes a plate-receiving slot having an axis perpendicular to the long axis of the handle and rotationally fixed to the handle. The clamp mechanism also includes a moveable jaw bordering the plate-receiving slot. A jaw tightening mechanism urges the moveable jaw against a bone plate positioned in the plate-receiving slot to thereby secure the plate in the vise. The bone plate is inserted into the vice and is clamped securely. The free end of the bone plate is bent or twisted using a bending iron. There are no provisions to control the location of the bend or twist or the amount of bend or twist. Since the wider portion of the bone plate is within the bone vice, it cannot be contoured to conform to the three dimensional shape of a bone.
U.S. Pat. No. 6,712,073 to Manderson discloses an extramedullary rod implant for long bones. A method for inserting a solid rod implant into the body is detailed by the '073 patent. The implant is designed for bridging two portions of a broken long bone, and maintaining the divided portions of the bone in stable alignment with each other. The solid rod implant is rigidly attached to the damaged long bone by a pair of partly tubular plates at either end of the rod. These plates provide the sole means of attachment of the implant to the bone. That is, there is no provision for any attachments along, beside or through any portion of the rod that would allow it to be attached to any portion of the bone providing support for osteosynthesis. By its design and method of rigid attachment to the bone through partly tubular end plates, the implant allows controlled motion at the fractured or non-united portions of the bone fragments. This motion stimulates rapidly forming external bridging callus formation for osteosynthesis of the long bone, a process that shortens the time of osteosynthesis of long bones so treated. This long implant is attached further from the bone fracture region using screws. The arrangement allows gentle movement at the fracture, which is said to promote the healing process. The shape of the implant rod and the attachment points are not contoured three dimensionally according to the shape of the bone. In fact, the fractured portion of the bone is not surgically disturbed and the implant is not set against the fractured bone.
U.S. Patent Application No. 2003/0055435 to Barrick discloses an orthopedic implant shaper. This implant shaper system consists of a flexible fiber optic curvature sensor device, a computer, and an implant-shaping machine. The flexible fiber optic curvature sensor device is a tape used to determine the required three-dimensional shape of an orthopaedic implant. The sterilized tape is applied to the fractured bone in surgery once it is reduced. The shapes and sizes of various metal orthopaedic implants are stored on the hard disc of the computer in a lookup table file. The operator inputs the type of implant to be contoured and the number of holes of a plate or length of a rod. The digitized contour of the tape is then matched with the particular bone implant. The information is transmitted to the implant-shaping machine to program the settings for the actual contouring. The implant-shaping machine consists of a series of opposing hydraulic cylinders with dies arranged in rows on rocking platforms. Each unit consists of a pair of opposing hydraulic cylinders that work reciprocally to move dies in relation to the metal fixation implant. In this invention, a fiber optic tape curvature sensor is placed on a bone that is fractured. The fiber optic tape is illuminated; the curvature of the tape placed on the bone is detected; and the information is sent to a computer, which controls implant-shaping machine. The implant is a machined device matching the exact dimension of bone curvature as detected by a fiber optic sensor tape. The strength of the implant, its biocompatibility and its means of attachment to fractured bone is not disclosed.
U.S. Patent Application No. 2004/0116934 discloses a tool system for adapting a bone plate. The tool system is for working on a bone plate and includes a first tool and a second tool. Both tools are used at the same time to shorten or bend the bone plate. The tool system for adapting bone plates is provided with a first tool having a first and a second introduction opening for bone plates, and a second tool having a third and a fourth introduction opening for bone plates. For cutting the bone plate, the bone plate is arranged in the first and third introduction openings, and for bending it is arranged in the second and fourth introduction openings. One or more of the introduction openings may be of closable construction in order to enable a bone plate which is to be worked on to be received such that it cannot come free. The two tools are used at the same time when shortening or bending the bone plate. This tool has an opening for cutting or shortening a bone plate and openings for bending the bone plate. The bone plate can only be cut at the ends of the bone plate and the bending movement is possible with the ends clamped by the tool. The precise location of the bend in the bone plate cannot be adjusted. The bone plate disclosed by the '934 application cannot be bent to a three-dimensional shape.
There remains a need in the art for a method and means for three dimensionally bending bone plates to provide three-dimensional support to fractured bone segments, thereby retaining the surgeon-set position of the bones during the bone-healing period. There is also a need for shaped bone plates that are suited for canine use; which can accommodate the small size of canine bone segments; which can be implanted so that the mobility of the operated animal is maintained immediately after surgery. Further needed is a bone plate system that provides intimate contact between fractured bone segments during the healing period, so that a long-term permanent bond between the implant and the underlying bone structure is made possible and extended motion meeting the canine needs can be achieved. Still further there is needed a bone plate system wherein the implanted bone plate is not removed during the remaining lifetime of the dog, and continues to function flawlessly without corrosion or rejection reactions throughout its service life.